1. Technical Field
The present invention relates to an image formation apparatus and an image formation system.
2. Related Art
An image formation apparatus such as a laser beam printer or the like is generally known in the art. The image formation apparatus of the related art is provided with, as a typical example of the configuration thereof, an image carrier that carries a latent image, a toner carrier that carries toner and develops the latent image that is carried on the image carrier by means of the toner, and a voltage application unit that applies a development voltage to the toner carrier for the purpose of the development of the latent image. The related-art image formation apparatus having the configuration described above operates roughly as follows. Upon the reception of an image signal or other kind of transmission signal from an external device such as a computer or the like, the toner carrier, to which a development voltage is applied by the voltage application unit, develops a latent image carried on the image carrier. By this means, a toner image is formed on the image carrier. Then, the related-art image formation apparatus transfers the formed toner image onto an image-formation target medium so as to form a final image thereon.
In the technical field to which the present invention pertains, some toner carriers have concave portions, that is, recesses or concavities, that are arrayed in a regular pattern. These regular concave portions are formed so that the toner carrier can carry a sufficient amount of toner on the surface thereof, which constitutes the main reason of the formation of these regular concave portions among other technical considerations. Although the plural form thereof is used here to refer to the recesses or concavities, it may be safely expressed as a concave portion. In the configuration of the toner carrier of the related art having the above-described regularly recessed surface, the concave portions function as a main region that carries toner. A few examples of the related-art image formation apparatus having such a configuration are described in JP-A-2006-259384 and JP-A-2003-57940.
Before the development of a latent image, toner that is carried by the toner carrier covers these concave portions, which means that these concave portions are not exposed. On the other hand, immediately after the completion of development of a latent image that is carried by the image carrier by means of toner that is carried mainly in the concave portions formed in the surface of the toner carrier, there is a possibility that (some of) the concave portions become exposed because the toner may not cover them immediately after the completion of development thereof. Or, in other words, in some cases, the concave portions might become exposed immediately after the movement of the toner, which was carried mainly in the concave portions, onto the image carrier. If the voltage application unit continues the application of a development voltage to the toner carrier even under the conditions that the concave portions thereof have become exposed, there is an adverse possibility that electric discharge occurs between the exposed concave portions thereof and the image carrier due to the continuously applied development voltage.